JP2001358900A - Image reader and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image reader having a simple structure and a miniaturized shape, for securing the stable traveling of a document surface and the read surface of an image sensor at the document read position of the front surface and back surface of a document sheet. SOLUTION: This image reader is provided with a first image sensor for reading the images of one surface of the document sheet, transported by an automatic document feed means, a second image sensor for reading the images of the other surface, a first platen 6 where the first image sensor is brought into contact with one surface of the document sheet at a prescribed read position, a backup guide 39 for guiding the document sheet to the side of the first platen 6 and a second platen 7 for supporting the other surface of the document sheet. The first platen 6 and the second platen 7 are connected and constituted to be flush with each other, and the second image sensor and the backup guide 39 are constituted integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for scanning a document image, optically reading the image, and outputting electronic data, and more particularly to an automatic document feeder usually called an ADF. The present invention relates to an image reading apparatus having two optical reading sensors (hereinafter, referred to as “image sensors”) for reading images on both sides of a document sheet fed one by one from a document receiving tray.

[0002]

2. Description of the Related Art An image reading apparatus usually called a scanner optically reads an image of a document, converts the image into electronic data, and converts it into an external personal computer, a copying machine, or the like.
The data is transmitted to an image forming apparatus such as a facsimile machine. Also,
An image forming apparatus usually includes such an image reading device.

The image reading apparatus has an image sensor for reading an image of a document sheet fed and fed one by one from a document receiving tray by an automatic document feeder. Further, in a recent image reading apparatus, an original sheet fed by an automatic original feeder is fed one by one by providing two separate image sensors so that the original sheet does not switch back and travel.
A document having a function configured to read images on the front and back surfaces of a document sheet in a single document transport pass has been proposed.

Examples of such an image reading apparatus having two image sensors for reading images on the front and back sides of a document sheet are disclosed in JP-A-11-32164, JP-A-10-126569 and JP-A-10-126569. −137164
No. 6,086,045.

Here, the image reading apparatus disclosed in Japanese Patent Application Laid-Open No. H11-32164, when reading the surface image of a document sheet, uses a reduction optical system using a CCD provided in a main unit of the image reading apparatus. There has been proposed a configuration in which an image sensor of the same size contact type for reading the back surface image of a document sheet is integrally mounted on the back plate of the image sensor using the reduced optical system image sensor that reads the image sensor.

The image sensor disclosed in Japanese Patent Application Laid-Open No. 10-126569 has a configuration in which both the front and back surfaces of a document sheet are read by a 1: 1 close contact type image sensor. A contact-type image sensor that is arranged in a unit and reads an image on the back surface is arranged on a scanner support that is connected to a main unit of the image apparatus by a connection shaft. Here, the scanner support is swingably supported by the connection shaft between the closed position and the maintenance position with respect to the main body unit, and the document transport unit is connected to the scanner support by the connection shaft. Is supported at a transport position or an open position so as to be swingable. With such a configuration,
In order to form a document conveying path having a predetermined height, the contact positions of the contact type image sensor for reading the image on the front side of the document and the contact type image sensor for reading the image on the back side of the document are shifted from each other, and the conveyance is performed. A configuration is adopted in which a pressure plate is provided on the surface of the path facing these contact type image sensors, and the pressure plate is urged in the direction of the transport path.

Further, in the prior art disclosed in Japanese Utility Model Laid-Open No. 2-137164, a contact type image sensor for reading an image on the front side of an original and an image on the back side are also provided in the same manner as in Japanese Patent Application Laid-Open No. 10-126569. A configuration is adopted in which the mounting positions of the contact image sensors to be read on the transport path are shifted from each other, and a platen roller is provided at a position on the transport path facing these contact image sensors.

[0008]

However, images on the front and back sides of a document sheet conveyed by an automatic document feeder are read by two separate image sensors without any so-called out-of-focus state. In order to set the transport document to the set reference position (travel position)
Need to be conveyed while maintaining the depth of focus.

In particular, when one of the first and second image sensors uses a close-contact type image sensor of the same magnification, the separation margin between the original surface and the reading surface of the reading device is determined by using a CCD. Since the size of the original is smaller than that of the reduced optical system image sensor, it is necessary to ensure a sufficient running property of the original sheet and the platen surface within a certain depth of focus.

Further, to make the image reading apparatus lighter and smaller in size, a reading position for reading one surface (front surface) of the document sheet and the other surface (back surface) of the document sheet are required. ) Needs to be brought as close as possible without separating the reading positions. Because ADF
When the two reading positions are arranged adjacent to each other in the transport direction, the image reading device must be lengthened in the document transport direction accordingly.

From such a viewpoint, all of the above-described image reading apparatuses according to the prior art ensure the stable running of the original sheet, reduce the size, and reduce the number of parts to reduce the failure occurrence rate. It was inadequate in doing so.

SUMMARY OF THE INVENTION The present invention has been made to solve such various problems of a conventional image reading apparatus, and has been made in consideration of the above-mentioned originals of the first platen and the second platen. A surface supporting the sheet forms the same plane, and the second image sensor and a backup guide for guiding the original sheet to the first image sensor are integrally formed, and Obtain a precise image data of both sides of the document while avoiding an increase in the length of the apparatus while sufficiently securing a stable running property in the traveling space between the document surface at the front and back document reading positions and the image sensor side facing the document surface. It is another object of the present invention to provide a small-sized image reading device having a simple structure.

[0013]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to an image processing apparatus for automatically and automatically feeding original sheets stacked on an original receiving tray one by one. An image reading apparatus for reading, comprising: a first image sensor for reading an image on one side of a document; a second image sensor for reading an image on the other side of the document; When the first image sensor reads the image of the one side of the original sheet conveyed by the first image sensor at a predetermined reading position, the first image sensor contacts and supports the one side of the original sheet at the reading position. A first platen of
A backup guide for guiding the conveyed document sheet toward the first platen, which is disposed at a position facing the first platen with the conveyed document sheet interposed therebetween, and conveyed by the automatic document feeder A second platen for supporting the original sheet from the one surface side so that the second image sensor reads an image on the other side of the original sheet to be read.
The platen and the second platen are configured such that surfaces supporting the respective document sheets are connected without any step to form the same plane, and the second image sensor and the backup guide are integrated with each other. It is intended to provide an image reading apparatus having a general configuration. Here, the first platen is formed of a transparent member, and the second platen is formed of a white opaque member.

The image forming apparatus according to the present invention is configured as described above, so that the original sheet supports the original sheet.
Ensures stable running between the two platens and the image sensor surface, enabling accurate reading of images on both sides of the document, and also reduces the number of parts required for ease of assembly and cost reduction. It was. Further, the document can smoothly travel on two platens formed on the same plane, and the focus on the traveling space between the image surface and the image sensor at the document reading position on the front surface and the back surface of the document sheet. As a result, it is possible to sufficiently guarantee the stable traveling performance with the ensured depth and to make the horizontal shape of the image reading apparatus small.

[0015] Further, the second image sensor and the backup guide are integrally formed and incorporated in an upper unit, and the first image sensor and the first platen are incorporated in a main unit. The upper unit is connected to the main unit using a hinge so as to be openable and closable, thereby improving the operability of the apparatus. Here, the original sheet is conveyed from the first platen side to the second platen side, and the first image sensor is constituted by an image sensor of a reduction optical system, and the second image sensor Is constituted by a close contact type image sensor of the same magnification optical system.

In the present invention, by providing a spacer for securing the space for transporting the original in a part of the upper unit or the main body unit, the travel space for the original sheet can always be kept constant. Further, there is provided a biasing means for applying a force in a direction opposite to its own weight, which is substantially balanced with the weight of the contact type image sensor of the upper unit, to the contact type image sensor; By providing the adjusting means for adjusting the relative position with respect to the original sheet, it is possible to provide a function of adjusting the running space corresponding to the thickness of the document sheet.

The present invention, on the other hand, provides an image forming apparatus including the image reading device configured as described above and forming an image based on the electric signal input from the image reading device. . The image forming apparatus includes a third platen for contacting and supporting a document placed at a document placement position adjacent to the first platen, and wherein the first image sensor is provided with a third platen. 3 has a function of reading an image of a thick original such as a book placed by traveling on the lower surface of the platen.

[0018]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing the overall configuration of an image reading apparatus according to a first embodiment of the present invention, and FIG.
1 is an enlarged sectional view of a main part of FIG. 1, FIG. 3 is a sectional view seen from the II direction of FIG. 2, and FIG. 4 shows a state where an upper unit of the image reading apparatus of this embodiment is opened upward. Figure 1
2 is a perspective view as viewed from the front side of FIG.

1 to 4, reference numeral 1 denotes a main body unit, and an upper unit 2 is attached to the main body unit 1 by a hinge 33 so as to be freely opened and closed. The outside of the main unit 1 is formed by a housing 3, and a paper discharge tray 4 is provided on one side surface of the housing 3. On the upper surface of the housing 3 on the side opposite to the paper discharge tray 4, as shown in FIG. 1, the upper unit 2 is opened upward, and a platen, which is a transparent glass plate on which a thick original or the like is placed and read, is placed. 5 (third platen) is incorporated.

On the opposite side of the platen 5 of the fixing portion 3b, which is a part of the casing 3 for fixing the platen 5, the document is conveyed one by one and the document is supported for reading the image. A platen 6 (first platen), which is a transparent glass plate, is a platen 7 (second platen) formed of an opaque white member that also supports the original to convey the original sheets one by one and read the image. And are fixed integrally. This fixing portion 3b
The end on the platen 6 side is cut out in a step shape, and the platen 6 is fixed to the step portion. The platen 6 and the platen 7 are rectangles having substantially the same shape, and their thicknesses are strictly equal. A fixing portion 3 for fixing the platen 7 is provided on the upper surface of the housing 3 similarly to the fixing portion 3b.
a is formed. A notch corresponding to the thickness of the platen 6 is formed at an end of the platen 7 on the platen 6 side, and the platen 6 is engaged with and fixed to the notch. In this way, both ends of the platens 6 and 7 are fixed to the fixing portion 3.
a and 3b, the other ends of which are fixed to each other, and their upper surfaces are connected to each other without a step to be fixed to the housing 3 so as to form the same plane.

A pair of discharge rollers 8 and 32 for discharging a document are provided at the end of the housing 3 on the discharge tray 4 side. One of the discharge rollers 8 is driven by a motor (not shown).

Inside the housing 3, a reduced optical system image sensor for converting a read and reduced image into an electric signal is housed. Reference numerals 9 and 10 denote carriages forming a part of the reduced optical system image sensor, and are driven by motors (not shown) to move inside the housing 3 in the left-right direction in the figure while maintaining a predetermined distance relationship in conjunction with each other. . The carriage 9 has a light source 11 for projecting irradiation light on the document at a fixed position or while moving, and receives a reflected light of the irradiation light projected by the light source 11 from the document and reflects the light in the horizontal direction. A reflecting mirror 12 for changing the direction into light is mounted. The carriage 10 includes a reflecting mirror 13 for turning the horizontal reflected light reflected from the reflecting mirror 12 into a vertical light beam, and the vertical reflected light reflected by the reflecting mirror 13 to the reflecting mirror 13. And a reflecting mirror 14 for changing the direction as reflected light in the horizontal direction opposite to the reflected light from the mirror 12. Reference numeral 15 denotes a lens for receiving reflected light from the reflecting mirror 14 and focusing on the received light. The light source 11 and the reflecting mirrors 12 to 14 and the condenser lens 15 of each carriage 9 and 10 form a reduction optical system image sensor.
Reference numeral 16 denotes an image sensor unit including a CCD that receives the reflected light focused by the condenser lens 15 and converts the reflected light into an electric signal. A lead wire (not shown) is connected to an output end of the image sensor unit 16, and an image signal obtained by converting reflected light from the document into an electric signal via the lead wire is connected to a copier body or a facsimile apparatus (not shown). It is transmitted to the main unit of the electronic device such as the main unit.

The outside of the upper unit 2 is formed by a housing 17 and an upper lid 20. A portion of the lower surface of the housing 17 corresponding to the platen 5 of the main unit 1 is provided with the platen 5
A pressing member 18 having elasticity for softly pressing and fixing a document placed thereon is fixed. The pressing member 18 is formed of a porous layer having a thickness that can be elastically deformed, and a flexible surface layer that covers the porous layer from below. Reference numeral 17a denotes a document receiving tray for stacking and placing documents to be conveyed one by one and reading an image. The document receiving tray 17a is formed with the platen 6 side lowered and inclined so that the document moves to the platen 6 side. At the end of the inclined surface of the platen 17a on the platen 6 side, a pair of feed rollers 19 and 22 sandwiching the platen 6 to supply the documents placed on the platen 17a one by one to the platen 6 are provided. They are provided so as to be in contact with each other. A part of the housing 17 on the right side of the paper feed roller 19 in the figure forms a flat portion 17b, and an original is placed between the flat portion 17b and an upper lid 20 containing a contact type image sensor described later. An opening 21 is formed for receiving the images one by one to be conveyed to the image sensor. An opening 2 is provided between the opening 21 and the platen 6.
A pair of paper feed rollers 40, 23 for transporting the original inserted from 1 to platens 6 and 7
2 are provided similarly. Also, the paper feed rollers 19 and 22
And the paper discharge roller 8, a document conveyance path 24 is formed through a pair of upper and lower plate-like bodies 45 and 46 including a flat portion 17 b. The paper feed rollers 19 and 40 are driven by a motor (not shown).

Reference numeral 48 denotes a document receiving tray 17a.
An upper guide for introducing a document sheet conveyed from the printer into the conveyance path 24 and a stopper for stopping the introduction of the document sheet, and operate at the timing of reading and feeding.

In the contact type image sensor in the upper cover 20, a light source 25 for projecting irradiation light for reading an image on the back surface (upward facing surface) of the document conveyed in the conveyance path 24; A protective glass 27 that transmits the irradiation light and the reflected light from the back surface of the document sheet; a cell hook lens 26 for converting the reflected light into parallel light; A line image sensor unit 28 and a circuit board 30 are connected to a contact image sensor (hereinafter referred to as CIS) unit 29.
Are fixed integrally. In the CIS, a plate-shaped backup guide 39 has a front end 39 in the transport direction.
The CIS unit 29 is integrally fixed by a. The backup guide 39 is pivotally supported by a pair of pivot pins 31 protruding from the left and right side plates 42 of the upper lid 20 (FIG. 3), and the CIS unit 29 pivots about the pivot pin 31. One end of a pair of left and right springs 34 for pressing the backup guide 39 downward is attached to the rear end 39b of the backup guide 39 in the transport direction (FIG. 3). It is attached to a spring support member 49 projecting laterally from above. As shown in FIG. 2, spacers 3 are provided at the left and right corners of the CIS unit 29 at the lower end on the side of the discharge rollers 8 and 32 as shown in FIG.
5 is fixed, and the distance between the lower surface of the CIS unit 29 composed of the backup guide 39 and the protective glass 27 and the transport path 24 between the platens 6 and 7 is set to an appropriate value so that each image sensor can receive the focused image. It is adjusted so that it becomes a proper interval.

The image reading apparatus according to the present embodiment is provided with a plurality of sensors (not shown) for detecting the position of a document and the presence or absence of an image on the document, and further, based on a detection signal of the sensor. Thus, the rotation driving operation of the motor (not shown), the movement operation of the carriages 9 and 10, the blinking control of the light sources 11 and 25, and the image sensor unit 16 and
A control circuit (not shown) for controlling the control circuit 28 is provided.

Next, the operation of this embodiment will be described.

When originals are supplied one by one to the first and second image sensors for copying or transmission, these originals are stacked and placed on the original receiving tray 17a of the upper unit 2. These originals are inserted one by one into the transport path 24 by the pair of paper feed rollers 19 and 22 through the opening 21.

The original is fed to each of the paper feed roller pairs 19, 22 and 4
The paper is supplied to the platen 6 through the conveyance path 24 by the reference numerals 0 and 23. At this time, the carriages 9 and 1 of the main unit 1 are
0 is the leftmost stop position in FIG. 1 among the movable positions. When the control circuit detects that the document has arrived on the platen 6 based on a detection signal from a document sensor (not shown), the control circuit sends irradiation light from the light source 11 to the document while the carriages 9 and 10 are stopped at the stop position. Emits light. This irradiation light passes through a platen 6 which is a transparent glass plate, is irradiated on the surface of the document, is reflected on the surface of the document to become reflected light, and is reflected by a condenser lens 15 via reflecting mirrors 12, 13, and 14. Incident. The reflected light that has entered the condenser lens 15 is focused on the image sensor unit 16 by the condenser lens 15, and a reduced image on the front side (downward facing surface) of the document is formed on the image sensor unit 16. Is done. The image sensor unit 16 transmits an electric signal corresponding to the reduced image to a main unit of the electronic device based on a control signal from the control circuit, and the main unit of the electronic device reproduces or transmits the image based on the electric signal. Do.

Next, the original sheet is moved onto the platen 7 facing the contact image sensor. At this time, since the platen 6 and the platen 7 are integrally formed and the upper surface of the platen 6 and the upper surface of the platen 7 form the same plane, the document is smoothly placed on the platen 6 from the platen 6. Move to The CIS unit 29 receives a clockwise rotation moment about the rotation pin 31 by a spring 34 and receives a counterclockwise rotation moment by its own weight. These moments are balanced, and when the upper lid 20 is opened upward, the spacer 35 which is formed to hang down slightly below the horizontal plane comes into contact with the upper surface of the main unit 1 when the upper lid is closed, and the floating state is established. Will be maintained. Thus, the CIS unit 29
Adjustment means for adjusting the relative position between the upper unit 2 and the upper unit 2 is formed. When the document sheet is located within the interval between the protective glass plate 27 formed by the spacer 35 and the platen 7, this interval is within a range in which a focused image can be formed on the image sensor unit 28, and will be described later. A sharp image can be read in the reading operation of the image on the back side of the document. When the upper lid 20 is closed, the spacer 35 is in contact with the upper surface of the platen 7 and the CIS unit 29 and the backup guide 39 are integrally floated to regulate the gap in the transport passage.

When the document arrives at the platen 7, the control circuit that detects that the document has moved onto the platen 7 based on a detection signal from a sensor (not shown) emits irradiation light to the light source 25. The irradiation light emitted by the light source 25 passes through the protective glass plate 27 and irradiates the back surface of the original. The reflected light is reflected by this back surface, passes through the protective glass plate 27 again, and becomes parallel light by the cell hook lens 26. Incident on the image sensor unit 28 of the CCD. The image sensor unit 28
Under the control of the control circuit, an electric signal corresponding to the reflected light is output to the main body of the electronic device, and the main body of the electronic device reproduces or transmits an image on the back surface of the document based on the electric signal.

The original on which the images on the front and back sides have been read is discharged from the upper cover 20 by the discharge roller pairs 8 and 32, and is deposited on the discharge tray 4.

Next, when an original is placed on the first platen 5 and an operation start switch (not shown) for instructing the start of a copying or transmitting operation is pressed, a platen is detected by a detection signal from a sensor (not shown). The control circuit that has detected that a document is present on the output 5 outputs a control signal for instructing the movement of the carriages 9 and 10, and moves the carriages 9 and 10 rightward in FIG. The control circuit simultaneously transmits a control signal for instructing the light source 11 to project irradiation light, and the light source 11 projects the irradiation light on the original surface on the platen 5 while moving to the right in FIG. Keep doing. Since the platen 5 is a transparent glass plate, the light source 1
The irradiation light from 1 transmits through the platen 5 and irradiates the original surface on the platen 5. The reflected light from the original surface again passes through the platen 5, is reflected by the reflecting mirrors 12, 13, and 14 like the transmitted light from the platen 6, and passes through the condenser lens 15 as a reduced image to form the image sensor unit 16. Image on top.
An electric signal corresponding to the reduced image is output from the image sensor section 16, and the electronic device reproduces or transmits the image of the document based on the electric signal.

In the present embodiment, the image on the front side of the document is read using a reduction optical system image sensor, and the image on the back side of the document is read using the contact type image sensor. The number of parts for regulating the vertical position of the original document is smaller than when reading the image on the front surface of the original document only with the close contact type image sensor with a small margin for separation from the original surface,
Ease of assembly and cost reduction are provided. Also,
The CIS unit 29 containing the close contact type image sensor for reading the image on the back side of the original sheet is configured to be placed on the platen 7 by its own weight, so that even when the original sheet is thick, a precise and stable image can be obtained. can get. Further, since the platen 6 and the platen 7 are configured in series so as to form the same plane by being in close contact with each other without forming a roller or a space therebetween, the document is smoothly placed on the platen 6 and the platen 7. And the horizontal dimension of the image reading apparatus can be made extremely small. Furthermore, since the document receiving tray 17a is located above the platen 5 where the image sensor does not exist on the upper portion, the vertical shape can be reduced.

FIGS. 5 and 6 are sectional views of a main part of a second embodiment of the image reading apparatus of the present invention. FIG. 5 is a longitudinal sectional view corresponding to FIG. 2 of the first embodiment, and FIG.
FIG. 6 is a sectional view taken along the line II of FIG. 5 and corresponds to FIG. 3 of the first embodiment. 5 and 6, the same components as those shown in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the backup guide 47 is integrally formed with the CIS unit 29 as a front guide 47a and a rear guide 47b in the front and rear directions in the transport direction. At this time, the rear guide 47
b functions to guide the document sheet. Guide members 44 having vertically long holes 43a and 43b therein are provided at both left and right ends of the upper surface of each of the guides 47a and 47b.
a and 44b are respectively set up at two places, and each of the long holes 43a and 43b
Support pins 20a and 20b protruding laterally from the side plate 42 of the upper lid 20 are inserted into the 3b so as to be vertically movable. Further, between the rear guide member 44b and the CIS 29, a spring holding portion 53 for holding a pair of left and right tension springs 36 between the upper surface of the rear guide 47b and the upper surface of the rear guide 47b is fixed laterally from the side plate 42.

In the present embodiment, when the upper lid 20 is opened, the pressing spring 36 raises the CIS unit 29 upward so as to balance with the weight of the CIS unit 29, and the CIS unit 29 raises the upper unit 2 Is maintained in a floating state so as to hang down slightly below the other surface. Therefore, the relative position between the CIS unit 29 and the upper unit 2 can be adjusted. As in the first embodiment, the upper unit 2 has a transport path 24 and a travel space suitable for transporting the document sheet. In this case, the position of the tension spring 36 is desirably close to the intermediate position between the guide members 44a and 44b erected in front and rear in order to uniformly apply the pulling force to the CIS unit 29.

Next, FIGS. 7 and 8 show adjusting means for adjusting the amount of protrusion of the spacer 35 for securing a running space. In FIG. 7, the spacer 35 is formed by a male screw member and is screwed with the female screw of the CIS unit 29. The protrusion amount can be adjusted by rotating the head portion 60 of the male screw up and down by rotating it with a screwdriver.

FIG. 8 shows an eccentric cam 61 attached to the lower part of each of the left and right ends of the CIS unit 29.
Since the protrusion 5 is formed, the amount of protrusion below the carriage can be easily deflected by rotation.

7 and 8, the ends of platens 6 and 7 having the same thickness are brought into contact with each other to be connected, and
The fixing portion 3a is extended toward the platen 6, and both platens are held and fixed from their bottoms.

The spacer 3 provided on the upper unit 2
5 and the spacer 3 at the same position on the main unit.
5 can also be provided.

As described in detail above, the image reading apparatus according to the present invention reads an image on one surface of a document using the reduction optical image sensor housed in the main unit, and reads the image on the other surface of the document. Since the reading is performed using the contact image sensor stored in the upper unit, the number of parts for regulating the vertical position of the document is smaller than when reading images on both surfaces of the document using the contact image sensor. , Ease of assembly and cost reduction. In addition, the platen for reading an image with the reduced optical system image sensor fixed and the platen opposed to the contact type image sensor are configured so that their surfaces form the same plane. As a result, it is possible to smoothly travel on the top and to make the horizontal shape of the image reading device extremely small.

As described above, according to the present invention, the traveling property of securing the depth of focus between the original surface and the reading surface of the image sensor at the original reading positions on the front and back surfaces of the original sheet is sufficiently ensured. An image reading apparatus with a simple structure and a small shape was realized while obtaining fine image data on both sides.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating an overall configuration of an image reading apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the embodiment shown in FIG.

FIG. 3 is a cross-sectional view as seen from the II direction in FIG. 2;

FIG. 4 is a perspective view of the image reading apparatus according to the embodiment shown in FIG. 1 when the upper unit is opened upward, as viewed from the front of FIG. 1;

FIG. 5 is a sectional view of a main part of an upper integrated unit of the image reading apparatus according to the second embodiment.

FIG. 6 is a cross-sectional view as seen from the II direction in FIG. 5;

FIG. 7 is a cross-sectional view showing an example of adjusting the protrusion amount of the spacer.

FIG. 8 is a cross-sectional view showing another example of adjusting the protrusion amount of the spacer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main unit 2 Upper unit 5 Platen (third platen) 6 Platen (first platen) 7 Platen (second platen) 9, 10 Carriage (reduction optical system image sensor) 11 Light source (reduction optical system image sensor) 12, 13, 14 Reflecting mirror (reduced optical image sensor) 15 Lens (reduced optical image sensor) 20 Top cover 20a, 20b Support pin 25 Light source (contact image sensor) 26 Cell hook lens (contact image sensor) 27 Protection Glass (contact image sensor) 28 Image sensor unit (contact image sensor) 29 CIS unit 30 Carriage (contact image sensor) 33 Hinge 34, 36 Spring (adjustment means) 35 Spacer 39 Backup guide 40a, 40b Slot (adjustment) Means) 42 Side plate 4 3a, 43b Elongated hole 44a, 44b Guide member 60 Adjusting screw 61 Eccentric cam

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H076 AA04 AA58 BA20 BA24 3F101 FB17 LA01 LB02 5C062 AA02 AA05 AB02 AB30 AB32 AB33 AC09 AC71 AD02 AD06 BA01 5C072 AA01 BA01 BA13 DA25 EA07 NA01 WA02

Claims (11)

[Claims] 1. An image reading apparatus for reading images on both sides of a document sheet conveyed by an automatic document feeding means for feeding out document sheets stacked on a document receiving tray one by one, comprising: For reading an image on one side of the
And a second sensor for reading an image on the other side of the document sheet.
When the first image sensor reads an image of the one surface of the document sheet conveyed by the automatic document feeder at a predetermined reading position, the image sensor reads the image of the document sheet at the reading position. A first platen for contacting and supporting one of the surfaces; and a first platen disposed at a position opposed to the first platen with the conveyed document sheet interposed therebetween, and A backup guide for guiding the document sheet to the first side; and the second image sensor reads the image of the other side of the document sheet conveyed by the automatic document feeder so that the document sheet is on the one side. And a second platen for supporting the document sheets from the first platen and the second platen. An image reading device, wherein the surfaces to be formed form the same plane, and the second image sensor and the backup guide are integrally formed. 2. The image reading device according to claim 1, wherein the first platen is formed of a transparent member, and the second platen is formed of a white opaque member. 3. The integrated second image sensor and the backup guide are incorporated in an upper unit, the first image sensor and the first platen are incorporated in a main unit, The image reading device according to claim 1, wherein the upper unit is connected to the main unit using a hinge so that the upper unit can be opened and closed. 4. A document sheet is conveyed from the first platen side to the second platen side.
An image reading device according to any one of the above. 5. The image sensor according to claim 1, wherein the first image sensor is constituted by an image sensor of a reduction optical system, and the second image sensor is constituted by a contact type image sensor of an equal magnification optical system. An image reading device according to any one of the above. 6. The image reading apparatus according to claim 1, wherein a spacer is provided at a part of the upper unit or the main unit to secure a space for the original to travel. 7. A biasing means for applying to said second image sensor a force in a direction opposite to its own weight, which is substantially balanced with its own weight of said second image sensor of said upper unit, is provided. Item 7. The image reading device according to any one of Items 3 to 6. 8. The image reading apparatus according to claim 3, further comprising an adjusting unit configured to adjust a relative position of the second image sensor with respect to the upper unit. 9. An image forming apparatus, comprising: an image reading device that reads an image on a document and converts the read image into an electric signal, and forms an image based on the electric signal input from the image reading device. A first image sensor for reading an image on one side of the document, a second image sensor for reading an image on the other side of the document, and a document sheet conveyed by the automatic document feeder. A first platen for contacting and supporting the one surface of the document sheet at the reading position when the first image sensor reads the image on the one surface at a predetermined reading position; A back which is arranged at a position facing the first platen with the conveyed document sheet interposed therebetween and guides the conveyed document sheet to the first platen side; And a second guide for supporting the original sheet from the one surface side so that the second image sensor reads an image on the other side of the original sheet conveyed by the automatic document feeder. Wherein the first platen and the second platen have respective surfaces supporting the document sheets forming the same plane, and the second image sensor and the backup guide. Wherein the image forming apparatus is integrally formed. And a third platen for contacting and supporting a document placed at a document placement position adjacent to said first platen, wherein said first image sensor comprises:
10. The image forming apparatus according to claim 9, wherein the apparatus is configured to read an image of a placed document by traveling on a lower surface of the third platen.
An image forming apparatus according to claim 1. 11. The image sensor according to claim 9, wherein the first image sensor is configured by a reduction optical system image sensor, and the second image sensor is configured by a close-magnification optical system contact image sensor. An image forming apparatus according to claim 1.